MSU July

Hello Everyone! Its been a while since I’ve wrote last, so I figured I would give a quick update on how the last few weeks have been going here at MSU! I am back on the night shift (from 4pm-2am) and for the most part, it has been pretty quiet the days I work. We had a night last week where we got in a few emergencies. We got in a horse that was showing severe colic signs, so it went straight to surgery. The horse ended up recovering well and went home several days after surgery.

This week, we had a mare come in on emergency that was possibly showing neurologic signs and/or foundering. Once she arrived, she received a quick neurologic exam and didn’t seem to be showing those neurological signs. The mare received a full work up with a physical exam, ultrasound, and blood work. Based on what was found, it is a concern that she may have Potomac Horse Fever. From my understanding, Potomac Horse Fever (or PHF) is an acute enterocolitis. Enterocolitis is an inflammation of the intestines. The pathogen that causes this is called Neorickettsia risticii. N. risticii is carried by mayflies and thought to be picked up by horses when they are grazing fields where mayflies have died. The horse ingests the mayfly thus also ingests the N. risticii. This causes the horse to produce signs of colic, fever, and diarrhea. PHF normally starts with the horse not eating and mild depression. Then the signs progress to fever, diarrhea, and colic. Up to a third of horses with PHF can develop laminitis. These signs are similar to signs seen in other types of enterocolitis, so it is important to do some diagnostic test to see what is causing it. To make a definitive diagnosis of PHF, N. risticii needs to be identified in the horses blood or feces by doing a cell culture or PCR. For treatment of PHF oxytetracycline is normally the go to antibiotic. Treatment is more successful the sooner it is given. The horse should respond rather quickly (within 12 hours). This should include a decrease in fever, increase in appetite, attitude becoming more bright and alert, and an increase in gut sounds. If laminitis occurs, keeping the legs iced will help decrease the inflammation that cause the P3 bone to rotate. If caught early, PHF is very treatable and prognosis is good.

Also this week, we got in a few more colics. They both ended up being fecal impactions. Treatment is similar for both of them. Treatment included oral and IV fluids, electrolytes, pain medication (such as Banamine, xylazine, detomidine, butorphanol, and lidocaine). The fluids are given to hopefully get the impaction moving and the pain medications help relieve the pain that comes along with that. Other than that, I just have been helping the night technicians with treatments and feeding the horses that are patients in the hospital. That’s all for now! I’ll keep you updated if any interesting cases come in!

Source for information on PHF: Merck Manual Veterinary Manual https://www.merckvetmanual.com/digestive-system/intestinal-diseases-in-horses-and-foals/potomac-horse-fever